Cornelsen Fokus Physik Lösungen

Give two ways of reversing the direction of the forces on the coil in the electric motor?

nikklg [1K]

Answer:

Interchanging the poles of the magnet

Reversing the direction of the applied current

Explanation:

The working of the electric motor is associated with Fleming's left-hand rule.
It states that if a current-carrying conductor is placed inside a magnetic field, it experiences a force in the direction perpendicular to the direction of the electric current and magnetic field.
These three physical quantities are placed in a mutually perpendicular direction.
So, in order to reverse the direction of force, you have to either change the direction of the current or magnetic field.

4 0

3 years ago

A 25,000 kg traveling east collides with a 2,000 kg truck standing still on the tracks. After the collision the train and truck

Elis [28]

Answer:

24.084 m/s

Explanation:

From the law of conservation of linear momentum

Total momentum before collision equals to the total momentum after collision

Since momentum=mv where m is mass and v is velocity

$M_{truck}V_{truck}=V_{common}*(M_{truck} +M_{standing})$ where $M_{truck}$ is the mass of the truck, $V_{truck}$ is velocity of the truck, $V_{common}$ is the common velocity of moving and standing truck after collision and $M_{standing}$ is the mass of the standing truck

Making $V_{truck}$ the subject we obtain

$V_{truck}=\frac { V_{common}*(M_{truck} +M_{standing})}{M_{truck}}$

Substituting $M_{truck}$ as 25000 Kg, $V_{common}$ as 22.3 m/s, $M_{standing}$ as 2000 Kg we obtain

$V_{truck}=\frac { 22.3 m/s *(25000 Kg +2000 Kg)}{25000}= 24.084 m/s$

Therefore, assuming no friction and considering that after collision they still move eastwards hence common velocity and initial truck velocities are positive

The truck was moving at 24.084 m/s

3 0

3 years ago

An airplane in a holding pattern flies at constant altitude along a circular path of radius 3.38 km. If the airplane rounds half

Andrej [43]

Answer:

a) 6076 m

b) 43.33 m/s

c) 68 m/s

Explanation:

(a) If the airplane rounds half the circle in 156s, its displacement is the circle diameter in 156s, or twice the circle's radius

s = 2r = 2* 3.38km = 6.76 km or 6760 m

(b) The average velocity would be displacement over unit of time

v = s/t = 6760 / 156 = 43.33 m/s

(c) The length of the chord it's swept in 156s is half of the circle perimeter

c = πr = π3.38 = 10.62 km or 10620 m

The airplane average speed is its chord length over a unit of time

c / t = c / 156 = 68 m/s

4 0

2 years ago

A car tire rotates with an average angular speed of 32 rad/s. In what time interval will the tire rotate 3.5 times? Answer in un

stiks02 [169]

Answer:

$\Delta t = 0.687\ s$

Explanation:

given,

Angular speed of the tire = 32 rad/s

Displacement of the wheel = 3.5 rev

Δ θ = 3.5 x 2 π

= 7 π rad

now,

Time interval of the car to rotate 7π rad

using equation

$\omega_{avg} =\dfrac{\Delta \theta}{\Delta t}$

$\Delta t=\dfrac{7\pi}{32}$

$\Delta t = 0.687\ s$

Time taken to rotate 3.5 times is equal to 0.687 s.

3 0

2 years ago

Consider a box sitting in the back of a pickup. The pickup accelerates to the right, and because the bed of the pickup is sticky

andreyandreev [35.5K]

The force would be coming from the right causing the box the lean/ slide to left, if it wasnt sticky.

8 0

3 years ago